Recently, an autonomous driving technology has been studied, so that an autonomous vehicle could be driven with a fairly high accuracy without an intervention of a driver. However, such autonomous driving technology may not work well in certain situations. For example, in case of a camera-based autonomous vehicle, if a field of view of a camera installed on the autonomous vehicle suddenly becomes dark, images acquired by the camera may not be appropriate for an autonomous driving, therefore the camera-based autonomous vehicle may not work properly.
In such a case, the autonomous driving should be stopped and the vehicle should be switched to a manual driving mode so that a driver is allowed to drive the vehicle manually. As a conventional technique, there has been a method for notifying the driver of a warning by using a geographic zones database which is a database including information on whether each of sections is safe for the vehicle to be driven autonomously or not.
A shortcoming of this prior art is that a manual driving may be required even in a section which was labelled as safe for the autonomous driving in the geographic zones database as the case may be. For example, in case a weather is extremely bad or a street light is broken at night, whether the vehicle should be driven autonomously or not cannot be determined properly by using a passively updated database like the geographic zones database. That is, a problem of the prior art is that it is difficult to deal with such a case.